Roller-mill



(No Model.) -2 Sheets- Sheet 1.

J. R. DAVIS, Jr. ROLLER MILL.

No. 258,027. Patented May 16, 1882.

@QQ/M. f @M @v LM-M (No Model.) 2 Sheets- 9.1113911` 2.

J; R. DAVIS, Jr.

ROLLER-MILL l No. 258,027. y Patente-May 16, 1882. l f 11.9. 2f

l V I z di UNITED y STATES PATENT CEFICE.,

JOHN R. DAVIS, JR., F NEENAH, WISCONSIN.

ROLLER-MILL.

SPECIFICATION forming part of Letters Patent No.`258,027, dated May 16, 1882, n Applicaiionled February 25,1882. (No model.)

.To all whom it may concern:

Beit known that I, JOHN R. DAVIS, Jr., ot'

Neenah, in the county of Winnebago and ,State of Wisconsimhave invented certain new and useful Improvements in Roller-Mills for Grinding Grain and other Purposes, ot' which the following is a specification.

Mills ot this description for crushing, compressing, grinding, or pulverizing material lo commonly have one roll of a pair arranged in ,fittedV bearings and the other in movable bearings, so that it may be adjusted in relation to or allowedtoyield from the former. The gearing driving these rolls has been so arranged that the lateral thrust due to their pressurecontact with each other, or the amountor nature ofthe material passing th rough, has been taken up bythe bearings in theshape of friction, and the greater the amount of material i zo going between them or the closer they were set together the greater would be this friction andthe greater the power necessary to ove rcome it. My invention consists primarily in means to z5 take up or obviate the friction due to this lateralthrust and restore it to the driving-power, and, secondarily, in a combination of frictionwheels and belts as a substitute for gearing for driving the rolls of a set at equal or differential speeds.

It will be sufficient to a proper understanding of the Inode in which itis put into practice to explain the invention in connection with a mill wherein the rolls are driven at dit'- ferential speeds. y

In the drawings, Figure 1 is a plan view of a roller-mill ot the latter description embodying the principles of my invention. Fig. 2 is a side elevation thereof; and Figs. 3 and 4 are 4o diagramsto illustrate the arrangement of the rolls and friction-wheels and the course of the belts. i

A is the roll in the stationary boxes, is driven from the main belt by means of the drumor pulley a on the end of its shaft a', and is the fast roll. Opposed to this is the slow roll B, mounted in movable bearings, which preferably yield against springs b, and are also provided with adjusting mechanism,.either for 5o their positive adjustment or forlimiting their advance and retreat-such, for instance, as

shown in Patent No. 240,282, granted to John Stevens on the 19th day of April, 1881. Y Upon 'the shaft a. of the fast roll, at or near each end thereof, are arranged friction-wheels a2, and upon a shaft, U, hereinafter called the friction-shaft, mounted in bearings() on the frame beyond said roll, are opposing friction-wheels c', driven thereby, which may be of the same diameter, or may be enlarged, as seen tit, to slow down the motion ofthe latter shaft. Pulleys c2 are also arranged near each end ot' the friction-shaft, outside the fratrie-work, oppbf' speed, the pulleys on the slow roll being for4 that purpose larger than those on the frictionshaft. The bearings of the friction-shaft are allowed to slide toward and from the fast roll, and to euch belt I apply a tightener-pulley, E, which, by its pressure, draws said shaft and bearings inward and holds the friction-wheels in biting contact with each other, so that the fast roll as it is driven by the main belt shall certainly drive back onto the friction-shaft and the latter return to the slow roll. By this arrangement the lateral4 thrust of the fast roll is opposed through the friction-wheels and belt to the lateral thrust of the slow roll, and is converted into, or rather not subtracted from, drivin g-pow'er, and the friction in the bearin gs is reduced to practically that which arises from the weight of the rolls.

I prefer to make the tightcner-pulleys adjustable, so that while straining the beltsthey can at the same time be made to take more or less ot' the pressure olf of the bearings.` The tighter the belts are made.the more the 'material is crushed or compressed by the rolls forced` the bearings of said ,rolls will be no more than4 if-they were running empty. Each tightener` may be independently adjustable, so as tooff-` set any dierence in the length of the belts;

but in the present instance I have shown both,

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for convenience, carried by a common shaft, e, mounted in a swinging frame, e', and held toward the belts by a coiled spring, e2, which is adjustable to increase or decrease the pressure by means of nuts e3. Instead of these nuts, a lever and rack may be employed. The friction-shaft can be pressed toward the fast roll by means of screws F, threaded into and through lugs f on the frame and abutting against or takinginto sockets in the bearingboXes of said shaft. Springs f are advisably interposed between the screws and the bearings, each spring being seated at one end against a collar or `jam-nut upon its respective screw and at the otheragainst the body of the corresponding bearing. If the springs are omitted, the screws will act in direct contact with the bearings, and the pressure will be positive instead of elastic.

rlhis device may either supplement or supersede the tighteners. The latter, however, I deem most beneficial, as they serve a dual function in both taking up stretch and increasing the tension or binding the friction-wheels together.

Should it be only desirable to drive the slow roll without the use of gears, and not to get any or all of th'e benefits above set forth upon all of the bearings, the friction-wheels and pulleys at that end at which the fast roll is driven may be dispensed with, excepting, of course, the main pulley. This will still give the advantage of reduced friction at the other end of A the rolls, and also of the employment of a long belt, which is much more certain in operation than a short one.

The friction-shaft can be dropped somewhat below the plane of the roller-shafts, as in Fig. 4, to eeonomize room inthe mill-frame and casing, and so far as the differential motion is concerned thiswill haveno badeffect. It will, however, fail to relieve the friction in measure with the departure from that plane, sincev the advantage of' having all three shafts in line with eachother is that the tension force is directly against the material being crushedthat is to say, the material passing between the rolls presses them directly away from each other, and if the friction-shaft is in line the tension will be directly against this outward pressure.

I claim as my invention- 1. The combination of' the driven roll, having a friction-wheel on its` shaft, a shaft on one side thereof, mounted in movable bearings and carrying an opposing friction-wheel and a pulley, a companion roll on the other side, having'also y on its shaft, and a belt connectii pulleys.

2. The combination of the driven roll, having friction-wheels at or near each end of its shaft, the friction-shaft on one side thereof', mounted in movable bearings and carrying opposing friction-wheels, and having pulleys at its ends, the companion roll on the other side, having also'pulleys on its shaft opposite to those on the friction-shaft, and belts connectin g said pulleys.

3. 'Ihe combination of the driven roll, the f necting driven roll and friction-shaft, the pulleys and belts connecting friction-shaft and companion roll, the tightener acting upon said belts, and means for adjusting said tightener as to the pressure it exerts..

5. The combination of the driven roll, the friction-shaft on one side thereof, the companion roll on the other, the friction-wheels connecting driven roll and friction-shaft, the pulleys and belts connecting friction-shaft and companion roll, and screws or equivalent devices arranged to move the bearings of the friction-shaft toward the bearin gs of the driven roll.

6. The combination of the driven roll, the friction-shaft on one side thereof, the companion roll on the other, the friction-wheels connectin g driven roll and friction-shaft, the pulleys and belts connecting friction-shaft and companion roll, the screws arranged behind the bearings of the friction-shaft, and springs interposed between said screws and bearings.

7. The combination of the driven roll, the vfriction-shaft on one side thereof, the companion roll on the other, the differential frictionwheels connecting driven roll and frictionshaft, and the pulleys and belt connecting friction-shaft and companion roll.

8. The combination of the driven roll, the

friction-shaft on one side thereof, the companion roll on the other, the 'differential frictionwheels conneetin g driven roll and frictionshaft, and the differential pulleys and belt running thereon, connecting friction-shaft and companion roll.

9. The combination of the driven roll, mounted in stationary bearings, the friction-shaft mounted in sliding bearings on one side thereof, the companion roll mounted in sliding bearings on the other side thereof, the frictionwheels connecting the driven roll and frictionshaft, the pulleys and belt conneetingfrietionshaft and colnpanion roll, and the tightener acting upon the belt to draw both sets of movable bearin gs toward the bearings ofthe driven roll.

JOHN R. DAVIS, JR.

Witnesses:

ALEX. MoNAUGHToN, JoHN SHIELLs.

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